This invention relates to coupons and labels and more particularly to composite coupons and labels and to manufacturing processes therefor.
My U.S. Pat. No. 4,281,762 discloses a composite in-store coupon having a top sheet and a base sheet wherein the top sheet has side portions permanently secured to the base sheet and a removable central coupon portion free of adherence to the base sheet. A central portion of the top sheet is detachable from the side portions and serves as a redemption, discount or promotional coupon, for example. This, of course, leaves the side portions with the base. Any copy or art work to stay on the removed coupon must be disposed within the confines of the removable center area.
Where it is desired to reduce the overall label structure size, a top sheet with no side portions is provided, and the copy or art work is printed thereon from one edge to another. Applicant has previously manufactured and sold a prior art label structure such as this, including a composite label having a removable top sheet which is adhesively, but removably, secured to a base sheet. The entire top sheet is removed from the base sheet and the top sheet does not retain any sticky adhesiveness or tackiness. Adhesives known in the industry as "fugitive" adhesives provide this removal function wherein no adhesive remains on the base. Such an adhesive is, for example, the adhesive sold as "EASY OFF" adhesive by Adhesive Products of New York, N.Y., under type production formula designation 1167-S2.
In manufacturing this structure, both sides of a top web are printed, the upper side of a pressure sensitive base web is printed, fugitive adhesive is applied, the webs are joined together, and thereafter the webs are die cut on a backing or liner web, all on the same equipment, to define individual labels, having top and base sheets, disposed on the backing web. This is similar to the manufacture of labels under the aforesaid patent, except that a fugitive adhesive is used and no perforations are cut to define side portions in the top sheets.
Such a procedure requires the use of a significant amount of adhesive; more so than would be used in other circumstances as will be explained. This use of excessive adhesive is believed to cause significant visual imperfections in the finished label, upon top sheet removal. These imperfections are believed to be due to the transfer of ink, or print media, between the top and base sheets, while the ink and the glue are still wet or viscous, spoiling the appearance of the receiving sheet.
More particularly, it is desirable to manufacture a label supply of composite labels on web fed printing apparatus running at speeds, for example, of 200-300 feet per minute. A top web is printed, for example, joined on the fly to a moving base web to which fugitive adhesive has been applied, and thereafter the top and base webs are die cut on the fly into individual labels. Due to the rapid movement of the two webs during joining and die cutting, it will be appreciated that it is difficult to maintain proper register between the webs, and between the top and base sheets during and after die cutting.
To insure proper register and orientation of the sheets, it has been found preferable to use a significant amount of the "fugitive" adhesive. Such adhesive, in its wet form, tends to hold the top and base sheets together during and after die cutting, and until the adhesive later cures. Use of excess amounts of such "fugitive" adhesive, while required for sheet orientation, is expensive.
It would be possible to use significantly less adhesive if the ultimate releasable securement of the sheets was the only goal, however, the manufacturing speeds and process require use of more adhesive than is otherwise required.
Normally, and apart from the added cost of the excess adhesive, its use would not present any problem. However, due to machine speed, and since at least the top web is printed immediately before joining to the base web by wet adhesive, the ink or other print media is still wet or damp when the top web is joined to the base web. It is believed that the wet or damp ink coalesces or otherwise transfers from the top sheet underside to the adhesive, and then to the base web, or remains with any small amount of adhesive which might be left with the base web when the top sheet is eventually removed as a coupon. Of course, a similar result is obtained when the base web is printed on the same press, and base web ink may transfer to the underside of the top sheet or removable coupon.
This transfer of ink or print media between webs or sheets is undesirable and occasionally spoils an otherwise acceptable print job. Any ink or other print media on the base is particularly distracting and detrimental.